This invention relates to the field of pneumatic actuators, and while not limited thereto, it has particular relation to the apparatus and method for positioning a pneumatic actuator disclosed in a commonly owned application Ser. No. 739,999, filed on even date herewith, Aug. 2, 1991.
The apparatus disclosed in that application includes an actuator wherein a movable member in the form of a piston is connected into a pneumatic pressure loop and caused to move linearly back and forth in response to the difference between the pressures applied to the opposite ends thereof. The operation of that apparatus includes regulation of the supply rate of pressure gas to the movable member through a closed loop feedback system which includes a microprocessor. It has been found in the development of that system that it is most advantageous that the path of the pressure gas in the pressure loop be as short as possible, and also that the pressure therein be sensed at a location or locations as close as possible to the valve controlling the pressure flow.